Commit fa8df343 authored by David Howells's avatar David Howells Committed by Jakub Kicinski
Browse files

scsi: iscsi_tcp: Use sendmsg(MSG_SPLICE_PAGES) rather than sendpage 



Use sendmsg() with MSG_SPLICE_PAGES rather than sendpage.  This allows
multiple pages and multipage folios to be passed through.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Reviewed-by: default avatarMike Christie <michael.christie@oracle.com>
cc: Lee Duncan <lduncan@suse.com>
cc: Chris Leech <cleech@redhat.com>
cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
cc: "Martin K. Petersen" <martin.petersen@oracle.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: open-iscsi@googlegroups.com
Link: https://lore.kernel.org/r/20230623225513.2732256-12-dhowells@redhat.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent eeac7405

drivers/scsi/iscsi_tcp.c

+10 −16
Original line number Diff line number Diff line
@@ -301,35 +301,32 @@ static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn, 


	while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) {

		struct scatterlist *sg;

		struct msghdr msg = {};

		struct bio_vec bv;

		unsigned int offset, copy;

		int flags = 0;



		r = 0;

		offset = segment->copied;

		copy = segment->size - offset;



		if (segment->total_copied + segment->size < segment->total_size)

			flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST;

			msg.msg_flags |= MSG_MORE;



		if (tcp_sw_conn->queue_recv)

			flags |= MSG_DONTWAIT;

			msg.msg_flags |= MSG_DONTWAIT;



		/* Use sendpage if we can; else fall back to sendmsg */

		if (!segment->data) {

			if (!tcp_conn->iscsi_conn->datadgst_en)

				msg.msg_flags |= MSG_SPLICE_PAGES;

			sg = segment->sg;

			offset += segment->sg_offset + sg->offset;

			r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset,

						  copy, flags);

			bvec_set_page(&bv, sg_page(sg), copy, offset);

		} else {

			struct msghdr msg = { .msg_flags = flags };

			struct kvec iov = {

				.iov_base = segment->data + offset,

				.iov_len = copy

			};



			r = kernel_sendmsg(sk, &msg, &iov, 1, copy);

			bvec_set_virt(&bv, segment->data + offset, copy);

		}

		iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bv, 1, copy);



		r = sock_sendmsg(sk, &msg);

		if (r < 0) {

			iscsi_tcp_segment_unmap(segment);

			return r;
@@ -746,7 +743,6 @@ iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session, 
	sock_no_linger(sk);



	iscsi_sw_tcp_conn_set_callbacks(conn);

	tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage;

	/*

	 * set receive state machine into initial state

	 */
@@ -777,8 +773,6 @@ static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn, 
			return -ENOTCONN;

		}

		iscsi_set_param(cls_conn, param, buf, buflen);

		tcp_sw_conn->sendpage = conn->datadgst_en ?

			sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;

		mutex_unlock(&tcp_sw_conn->sock_lock);

		break;

	case ISCSI_PARAM_MAX_R2T:

drivers/scsi/iscsi_tcp.h

+0 −2
Original line number Diff line number Diff line
@@ -47,8 +47,6 @@ struct iscsi_sw_tcp_conn { 
	/* MIB custom statistics */

	uint32_t		sendpage_failures_cnt;

	uint32_t		discontiguous_hdr_cnt;



	ssize_t (*sendpage)(struct socket *, struct page *, int, size_t, int);

};



struct iscsi_sw_tcp_host {